Session, LinComb, and CostSum — the three builders the roster scope doc
excludes — re-shape onto the args seam (refs #271): builder() is now
zero-arg and returns a pending recipe (Session: tz + open; LinComb:
arity; CostSum: n_costs), the full signature forms in make, and
configured(...) is the Rust-path convenience producing the identical
recipe (twin-pinned). Session's period_minutes becomes a real ParamSpec
bound by configured instead of a baked struct field — same behaviour,
now sweepable when left open. Session::new and SessionFrankfurt are
untouched.
All builder(n)-form call sites move mechanically to configured(n):
aura-runner member.rs (wrap_r), aura-composites (vol_stop/cost_graph),
aura-engine blueprint.rs + e2e tests, aura-ingest breakout example,
and the crates' own tests. aura-std drops its unused chrono/chrono-tz
deps (stale since the b39fd63 session move).
The roster is deliberately untouched here: rostering before the op
seam lands would expose unconfigured pending builders to add_node.
claude
e84ad6d0d2